1. Field of the Invention
This invention relates to cone type crushers.
More particularly, the invention concerns a bearing system for a cone type crusher assembly which is supported on the underside alone and free on its upper side, the bearing system preventing irregular wear of bearings due to metallic contact resulting from localized impact loads by means of cooperative action of vertically distributed bearing structures and a spherical bearing structure while in spite of its unique construction permitting free vertical movements of the rotary crusher assembly even under torque transmitting condition for adjustment of the exit clearance of the crushing chamber in automatic operations.
2. Description of the Prior Art
As illustrated in FIGS. 1 and 2, the cone type crusher of this sort generally includes a crusher support frame 1 with a fixed vertical cylinder 34 at the center of its bottom portion, and an eccentric drive cylinder 8 loosely fitted on the cylinder 34 and having a follower gear 6 around its eccentric outer periphery to gyrate a crusher assembly 20.
In such a crusher, it is the general practice not to support the upper side of the crusher assembly 20 by a bearing and to provide a bearing only between a bottom cylinder 35 of the crusher assembly 20 and the eccentric drive cylinder 8 for preventing the frictional wear from being localized to the inner wall surface of the fixed frame 1 under the influence of the feed material and by reason of unhindered, very smooth feeding of the material. In this case, the crushing load is imposed perpendicularly to the outer conical face of the crusher assembly 20 and the load moment is received in the direction in which the crusher 20 falls. Since the moment is received solely by a bearing 36 which is provided at one position in the conventional bearing structure as shown in the drawings, the cylindrical surface of the bearing 36 is brought into metallic contact with one side of the eccentric drive sleeve 8. As a result considerable localized frictional wear takes place not only on the bearing 36 but also on the surface of the eccentric drive cylinder 8. This detrimentally impairs the service life of the crusher and accelerates deteriorations in its crushing ability particularly in a crusher of the above-mentioned type which involves impact load and instrusion of crushed dust during operation.
In addition, the crusher assembly 20 is provided with not only a radial bearing but also a thrust bearing. In this connection, the conventional practice has been to provide a spherical bearing 37 on top of a cylindrical main shaft 15 which is passed through the eccentric drive cylinder 8. Therefore, the crushing load received by the spherical bearing 37 imposes a bending moment on the main shaft 15 or a main shaft bearing 16.
On the other hand, in order to cope with these problems, an attempt has been made to lessen the concentration of load on the bearing 36, supporting the spherical bottom face of the crusher assembly 20 on the fixed frame 1 as shown in FIG. 3, thereby by generating opposite resistant moment about the bearing 36. However, as seen in that figure, this arrangement does not permit movement of the main shaft 15 in the axial direction, and the upper portion of the fixed frame 1 has to be rotatingly adjusted by screws in order to adjust the exit clearance of the crushing chamber. It is therefore impossible to adjust the exit clearance automatically during the crushing operation. The adjustment of the exit clearance requires stoppage of the operation and involves jobs which are very troublesome and which take time and labor detrimentally to the efficient crushing opeation. Further, the complicated construction is apparently disadvantageous costwise.